Method and apparatus for transmission of pictures



May 21, 1935. M. D. M'c FARLANE METHOD AND APPARATUS FOR TRANSMISSION OF PICTURES Filed Dec. 1, 1931 RELAY Bok 8 Sheets-Sheet 1 3 UNIT COMBINATION PUNCH 3 umr TRANSMITTER RELAY BANK {AND DISTRIBUTORS .5 UNIT COMBINATION PUNCH f 5 unn- TAPE 5 unrr TRANSMITTING APPARATUS LINE, CABLE OR AERIAL 5 UNIT TRANSMITTER 5 UNIT REcEwme APPARATUS PUNCHING RELAY BANK AND DISTRIBUTERS LIGHT GHT BOX .5 UNIT TAPE INVENTOR ATTO R N EYS M y 2 1935- M. D. MCFARLANE 2,00 0

METHOD AND APPARATUS FOR TRANSMISSION OF PICTURES Filed Dec. 1, 1931 8 Sheets-Sheet 2 39 42 CABLE, LINE ORAERIAL I a :0 :0 Z a 50 IL PERFORATOR .SUNITTAPE RELAY BANK AND msrmaurons E'LECTRICALLY OPERATED SHUITERS FILM new EXPOSED (0 f8? @mqM uo oe 0 HOLES C) Q Q Q 0 0 5355 QQ DG C) OQ OQ O CD 0 Q Q 0 Q Q Q fia l iifim.

1 BY ipw ATT R N EYS May 21, 1935.

M. D. M FARLANE METHOD AND APPARATUS FOR TRANSMISSION OF PICTURES Filed Dec. 1, 1931 8 Sheets-Sheet I5 A u R PHOTO ELECTRIC SOURCE OF CELL I {RELAY Box A 4 I a 7 8 GEAR BOX 4 4 {RELAY BANK j I ORIGINAL PICTURE I 14 ELECTRKI r 5 I! DRIVING MOTOR 5 UNIT COMBINATION 36 PUNCH 37- .rSImn-TAPE TRANSMImIIe I xAPHARATUS 3 LINE,CA8LE on AERIAL 6 RECEIVING RELAY BANK -w r APPARATUS 1 -(NOTAPUNCH) ("I .9 MECHANICAL CONNECTIONS 3 UNIT Puupn BUNIT TAPE/L eLac'rmc MOTOR 5 I co FILM j 2 FY INVENTOR '251 ad/10am 3mm B TAPEM W ATT NEYS y 1935- M. D. MCFARLANE 2,002,208

METHOD AND APPARATUS FOR TRANSMISSION OF PICTURES Filed Dec. 1, 1951 8 Sheets-Sheet 4 INVENTOR y ,1 M. D. M FARLANE 2,002,208

METHOD AND APPARATUS FOR TRANSMISSION OF PICTURES Filed Dec. 1, 1931 s Sheet-Sheet 5 5 mm TRANSMITTER INVENTOR mz z-m Q ATT RNE'YS May 21, 1935.

M.D.M FARLANE METHOD AND APPARATUS FOR TRANSMISSION OF PICTURES as -o 3 i -1 D 2 x X .C- I) O l- Filed Dec. 1, 1931 8 sheets sheet 6 O ZJ B). (D C 4 11 m G 0 O G O O X 2 H I OOC) OQC).

INVENTOR M$M I A NEYS y 1935- M. D. MCFARLANE 2,002,208

METHOD AND APPARATUS FOR TRANSMISSION OF PICTURES Filed Dec. 1, 1951 8 Sheets-Sheet 8 .97 A O F v u1 3unrr TAPE TRANSMITTER .98

o v \rv --a Q BMMMAM PUNCH FOR 5 UNIT LOGARITHMIC TAPE C3 )--O 006 O G g cg- -e 0 00 6 9 g---Q 0 0 @0 g g--@ Q 0 0 0 A ORNEYS Patented. my 21, 1935 UNITED STATES METHOD AND PATENT OFFICE APPARATUS FOR TRANS- 39 Claims.

The present invention relates to the transmission of pictures or the like by use of code combinations representing tone values of elemental areas ofthe pictures.

The invention may be carried out in different methods and by a variety of diflerent types and kinds of apparatus but for the purpose of the present disclosure, the specific form of apparatus chosen is that of tape transmission.

As illustrating the present invention, a code of three units is chosen as the basic code, and from this code of three units, eight distinctive picture tone values are obtainable and this basic code is superimposed on a greater unit code for transmission purposes. When referring to the three unit code, it should be understood that any unit code may-be used as a basic code, provided the basic code be of lesser combinations than the transmission code. The three unit code is used as the preferred basic form because it oflers a certain practical balance between perfection of result and cost and time of transmission.

One particular feature of the invention is the superposing of the three unit basic code on a different code system used for transmission, for example, a five unit code system is chosen as the transmitting code, whereby a three unit code is transmitted by the selection of five elements of live points in a five unit transmission tape. The three unit code may also be translated directly into a six unit code for a tape transmission system.

The desirability of superimposing the tree unit code upon five or six unit systems resides in the fact that five unit and six unit codes are commercially used codes.

There is a further important feature of the present invention which resides in the conversion of this three unit code into a set-up or intermediate record which will correctly expose a photographic film or plate. This three unit code as prepared from the original and then translated into a five or six unit code for transmission purposes, produces at the receiving end a five or six unit code signal or record of the same character as was used at the sending end, which in turn is retranslated back into the three unit code. this received tape be used directly to control exposures for unit areas of a sensitive plate or fihn, it will be found that the ratio of the units of the code will not produce correct tone values in the exposed plate or film, the reason for this being that the emulsion on the plate or film has an exponential or logarithmic exposure ratio. Therefore, according to thepresent invention, preferably, the received tape is run through a device which cooperates with the three unit code to give a logarithmic exposure, or the three unit code is converted into a tape having logarithmic value relations. Under certain conditions other than true logarithmic exposures are provided for as hereinafter more fully explained. This same operation may be carried out withoutthe use of tape by setting up the combinations upon lock-up relays or other mechanical or electrical apparatus, tape being chosen as thepreferred and the simplest method of explaining 'applicants invention.

The present invention includes the steps of producing a transmission shortened tape at the sending end, transmitting this tape to produce the same shortened tape at the receiving end, then converting the received shortened tape into a logarithmic code tape which is a long tape, thereby obtaining proper high grade pictures at the receiving end while saving time and money in the transmission by the use of .a shortened tape.

Diagrammatic disclosures have been used, as is common practice in this art, to obviate needless explanation and drawings, since the present disclosure is addressed to those skilled in the art who will readily fill out the diagrams with the proper elements by merely usingv the well known skill in this art.

It is to be understood that the disclosure herewith is made in accordance with the patent laws and is not intended to be understood in the limiting sense, in view of the fact that the inventions may be carried out by one skilled in the art by slightly varying the apparatus and the methods herein disclosed.

Fig. 1 is a diagrammatic lay-out of a sending station in accordance with the present invention.

Fig. 2 is a diagrammatic lay-out of a receiving station according to the present invention.

Fig. 3 is a diagrammatic lay-out of a modification of the receiving station;

Fig. 4 is a diagrammatic lay-out of a modification of the sending station.

Fig. 5 is a diagrammatic lay-out of a receiving station cooperating with the sending station shown in Fig. 4. 7

Fig. 6 is a diagrammatic lay-out of the relay bank and distributors at the sending station as utilized in Fig. l.

Flg. '7 is a diagrammatic lay-out of the relays and distributors as used at the receiving end in Fig. 2.

Fig. 8 illustrates a tape punched in accordance with the three unit basic code on which the picture is analyzed.

Fig. 9 illustrates the three unit code superimposed on a six unit code tape.

Figs. 10, 11 and 12 illustrate the three unit code superimposed upon a five unit code tape.

Fig. 13 diagrammatically illustrates an optical arrangement for producing logarithmic light values irom. a three unit code tape in order to obtain unit area exposures of a uniformly graded scale.

Fig. 14 illustrates diagrammatically an arrangement of mirrors whereby the logarithmic light values desired may be obtained from a three unit tape.

Fig. 15 illustrates the relation between the logarithmic light values and a three unit tape.

Fig. 16 illustrates a diaphragm and a. logarithmic five unit code tape produced from a three unit code.

Fig. 17 diagrammatically illustrates an apparatus for translating a three unit code tape into a logarithmic five unit code as illustrated in Fig. 16.

Fig. 18 illustrates the relation between the three unit code tape and a logarithmic code tape of five units as shown in Fig. 16.

It has been found that eight tones are satisfactory for picture transmission and reproduction of certain commercial classes. Eight tones may be obtained by a three code combination wherein no signal is considered as one tone, preferably black, and three signals as the eighth tone, preierably white. The majority of commercial tape transmitters work on either fiveor six unit codes, therefore, it an eight tone picture code is recorded on such a commercial tape three-fifths or one-hall (dependent on whether the five or the six unit code system is used) of the available code space is wasted, sinre the eight tones require only three unit positions on the tape. Now by superimposing the three unit code on a five or six unit code transmitting tape so as to fill all the available spaces on such tape, a substantial saving in transmission time is accomplished. Then at the receiving stations the received code signals are retranslated into the three unit code so as to produce a picture of eight tones.

Referring now to Fig. 1, which diagrammatically illustrates an apparatus for sending picture signals in accordance with the present invention, the original to be transmitted is mounted upon a drum 1, which is carried by a lead screw 2 that is driven through a suitable gear box 4 by an electric motor 5. A source of light 6 projects a spot of light on the original picture on the drum I and the rays from the spot of light are reflected to a photo-electric cell 1. As the lead screw 2 is rotated by the electric motor, the spot of light from the source I scans the entire picture and causes varying electrical currents to pass through the photo-electric cell 1. The photo-electric cell 1 is connected with an amplifier 8, of, any type known in the art, which amplifies the current and transmits the same to a relay box 9 comprising marginal relays set to respond to a three code system covering eight tones of the original. The relay box I is electrically connected with a three code punch II of a type well known in the art, which in turn is controlled by the lead screw 2 to determine the number of unit areas scanned during each rotation of the lead screw. The relay box 9 may also be connected with the lead.

members will bear against the other bar.

screw 2 to reset the relays after each punching operation. The result of the mechanism thus far described is to produce a three unit code tape i i on which may be registered eight tone values of the original picture being scanned, there being one code signal for each unit area of the original picture. This three unit tape runs directly to a three unit transmitter I! which transmits the code signals on the three lilzlit tape ii to distributors and a relay bank These distributors and the relay bank are diagrammatically illustrated in Fig. 6. The three unit transmitter It comprises three contact members I5, I 6 and I1 operating between contact bars I! and IS. The contact members l5, l6 and H are controlled by the tape II and these contact members are either in contact with the contact bar It or the contact bar l9. There is no neutral position of the contact members except for the moment when these members are moving. If there are three omnings in the tape ll, then all three contact members will bear against one contact bar. If there are no openings in the tape ll, then all three contact If there is one opening in the tape, one contact member will bear against one bar and the other two will complete connections through the other bar. These three contact members l5, I6 and H are electrically connected with solid rings 20, 2| and 22 of the distributor 24. Adjacent the solid rings 20, 2| and 22 are commutator rings 25, 26 and 21, each of which have ten segments, making thirty segments in all. These thirty segments are connected with theoperating coils of thirty polarized relays 2B comprising a bank of relays, adaptedto be operated in accordance with the signals from the transmitter II. The contacts 29 of the polarized relays 28 are connected with the commutator segments of another distributor 30 having five commutator rings, each divided into six segments, making thirty segments in all. The solid rings 3| of this distributor are five in number and are each respectively connected with selector coils 32 of a five unit punch. The three unit distributor 24 carries a rotating brush arm 3 having double brushes which cover a commutator ring and its associated solid ring. The five unit distributor 30 likewise has a rotating brush 35 which also carries double brushes covering a commutator ring and an associated solid ring. In both cases. the brushes are insulated one from another and this may be done by utilizing an insulator as the rotating brush arm. In order to avoid confusion, only a few the circuits are shown as connected. It is to be understood that each segment of the commutator of the three unit code distributor 26 is connected directly to a corresponding operating magnet in the bank of polarized relays and that each contact of the polarized relays is connected directly with a segment on the five unit distributor 30. It is also to be understood that there is sufiicient neutral space between each adjacent segment of the commutators to permit time for feeding the tape being read and punching and feeding the tape being punched. These feeding mechanisms are so well known in the art of tape readers and tape punchers that mere reference thereto is suiilcient to fully advise those skilled in the art as to these devices.

In view of the fact that the relays 28 are of the polarized type, it will be observed that the relay setting once made by the three unit transmitter retains its set code combination until a new combination is set up through the three unit transmitter. It will be observed that the rotating brush arm 34 on the three unit transmitter 24 is spaced 180 from the rotating brush arm 36 of the five unit transmitter. Therefore,

it will appear that while the three unit distributor 24 is setting up combinations in the upper three rows of the polarized relay bank, the five unit distributor 39 is reading the lower three rows of the polarized relay bank, and when the three unit distributor 24 is setting up combinations in the three lower rows of the relay bank, the five unit distributor 30 is reading the three upper rows of the relay bank. From the wiring illustrated in Fig. 6, it will be observed that the three unit distributor 24 sets up three unit code signals in vertical lines in the polarized relay bank and it will be observed that the five unit distributor 39 reads the set-up signals as horizontal lines, there by superimposing a three unit reading code on a five unit transmitting code. This will be more clearly explained with reference to the tapes illustrated in Figs. 8 to 12 inclusive.

Returning now to Fig. l, the selector coils 32 illustrated in Fig. 6 operate the selectors for the five unit code punch 36, which produces a five unit tape 31 that passes to the transmitting apparatus 38 which transmits the five unit signals to the line, cable, or aerial 39, as the case may be.

Fig. 2 illustrates a receiving system in which the five unit code on the line 39 is received by a five unit receiving apparatus 49 which punches a five unit tape 4| that is a reproduction of the five unit tape 31 at the sending station. This five unit tape 4| is fed to a transmitter 42 which transmits the code signals on the tape 4| into electrical impulses. A transmitter 42 is electrically connected with distributors and a relay bank 44 that is similar to the distributors in relay banks illustrated in Fig. 6. The distributor and relay bank at the receiving end is illustrated in Fig. '1 and comprises a five unit distributor 45 having five solid rings 46 and five adjacent commutator rings 41. Each of the commutator rings 41 is divided into six segments. The solid rings 46 are directly connected with the transmitter 42 which reads the five unit tape 4| and transmits either the plus or minus current for each reading of the tape. The bars of the commutator rings 41 are connected with the actuating coils 48 of the polarized relays in the polarized relay bank. The contacts 49 in the polarized relay bank are connected with the segments of the commutators 59 of the three unit distributor 5| and the solid rings 52 of the three unit distributor are connected with selector magnets 54 of a three unit punch 55.. The five unit distributor 45 is provided with a brush arm 56 and the three unit distributor 5| also has a brush arm 51. The brush arms 56 and 51 are rotated at the same rate of speed preferably being mounted on the same shaft and are spaced 180 apart relative to the polarized relay bank so that when the five unit distributor 45 is setting up the upper three rows of polarized relays, the three unit distributor 5| is reading the three lower rows of relays, and vice versa. From the arrangement of the wiring, it will be observed that the five unit distributor 45 sets up the polarized relays five at a time in horizontal rows, there being five relays set for each code signal in the five unit tape, while the three unit distributor reads the relays three at a time in vertical rows. It will be observed that the operation oi the receivingdistributors and relay bank is exactly the opposite of a similar instrument at the sending end. and in view of this fact switch arrangements may be employed to permit the same apparatus to be used at one time for sending and at another time for receiving. The sending end superimposes a three unit code on a five unit tape, while the receiving end translates the five tape back into a three unit code which corresponds to the three unit tape at the sending end which contains eight tone values of the original picture being transmitted.

Referring new again to Fig. 2, the three unit punch 55 produces a three unit tape 8, which is passed to the reproducing instrument comprising a cylinder 59 carrying a light sensitive film in a light tight box 60 which film is exposed by the source of light 6| producing rays of light which pass through the openings in the three unit tape 58. An electric motor 62 is operatively connected with the five unit transmitter, the relay bank and distributors 44, the three unit punch 55. feed mechanism 64 for the tape 58, and the cylinder 59 carrying the light sensitive film. In this way, the several units are run in proper speed and synchronism. It is to be understood, however, that the exposure mechanism comprising the cylinder, light tight box, sourceof light, etc., may be entirely separate from the three unit punch, and, therefore, may be operated at a difierent speed from the other receiving devices. In this case, a separate electric motor is provided to operate the tape feed mechanism 64 and the cylinder 59, which cylinder is mounted on a lead screw as is well known in the art in order to cause a proper movement of the cylinder relative to the spot of light being projected thereon in order to provide the proper exposure of unit areas on the film.

Fig. 3 illustrates a simplified mechanism for receiving the signals. The signals coming in on the line 39 are received by the receiving periorator 49 which produces the five unit tape 4| which is read by the transmitter 42 and the signals are fed to the distributor relay bank 44. The output from the three unit distributor (Fig. 6) instead of leading to the selector magnets of a three unit code punch lead directly to shutters 65, 66 and 61 in the light tight box 60. These shutters operate exactly the same as the punch magnets would operate to punch a tape. In other words, if the signal coming in would ordinarily punch one hole in the tape, the signal in the present case operates to open one light shutter and in this way, the signals directly control the light falling on the cylinder 59 without the intervention of the three unit code tape. In this case, the electric motor 62 is mechanically connected with a transmitter 42, the distributors and relay bank 44, and the drum or cylinder 59, in order that these parts may at all times operate in the proper relation.

Fig. 4 illustrates a modification of the .invention at the sending station. In this modification, the relay box 9 insteadof producing a three unit tape is connected directly with the solid rings 20, 2|, and 22 (Fig. 6) of the distributor 24 so that the reading of the marginal relay box 9 goes directly to the distributor 24 and into the bank of polarized relays and out of the five unit distributor to the five unit punch 36 which produces the five unit tape 31 that is transmitted by transmitter 38 to the line 39.

Fig. 5 diagrammatically illustrates a receiving station wherein the five unit signals on the line 8. are received by a receiving apparatus -A,

common in the art which is not a punch but merely a receiving device. The electrical signals from the receiving apparatus llA are transmitted directly from the distributor of lll--A to the relay bank ll which is the same as the construction disclosed in Fig. 7 with the exception that in the place of the five unit distributor reading a tape the signals come directly from-the distributor of the receiving apparatus llA. The output from the relay bank 44 goes to the selector magnets 54 (as shown in Fig. 7) of the three unit punch 55 which produces the three unit tape 58 that is synthesized into the picture in the manner previously described with reference to Fig. 2.

In order to simplify the diagrams comprising Figs. 1 to 5 of the drawings, lines terminating in solid round dots are used to represent suitable electrical connecting lines or cables, and lines ending in arrow-heads are used to designate suitable mechanical connections. These features are merely skill of the art and do not per se, comprise the present inventions. It is also obvious to one skilled in the art that the apparatus herewith disclosed may be readily connected to translate a three unit code into a five or six unit code and transmit and receive the signals without the use of tape. That is, the picture may beanalyzed on one code which is superimposed on adifferent code for transmission, and wherein the kind of transmission may be of any well known type. The tape type of transmission is preferred because a record is made both at the sending and at the receiving stations. These records may be checked in case error occurs, and the transmission by tape permits the transmission to be interrupted and resumed without loss of the signals that have been sent out.

Figs. 8, 9, 10, 11 and 12 all illustrate types of tape, and in these illustrations, the open circles merely indicate positions which in the actual tape would be a blank surface. The heavy dots indi-- cate punch openings where holes would be punched in the actual tape.

Fig. 8 illustrates the three unit code or basic tape which is being utilized as illustrative of the basis of the present invention. It is to be understood that other combinations or codes may be utilized for the basis. In order to easily follow the code combinations, the different positions for one complete code are indicated by being connected with a thin line, and the code combinations are designated by letters of the alphabet. These letters are arranged in groups of three; A, B, C, representing the code for black or merely blank spaces across the tape; D, E, F show D perforated and is the next tone to black; G, H, I show H perforated and is the third tone; J, K, L illustrates J and K perforated and is the fourth tone; M, N, 0 illustrates O perforated to make the fifth tone; P, Q, R illustrates P and R perforated to make the sixth tone; S, T, U show T and U perforated to form the seventh tone; V, W, X all being perforated comprise white or the eighth tone.

Fig. 9 illustrates the scale of code combinations shown in Fig. 8 directly transposed to a six unit tape, in which groups of three units are arranged on opposite sides of the feed hole perforations 61.

In Fig. 10, the code combinations from Fig. 8 are shown as arranged in groups of three longitudinally of the tape with the first group in a longitudinal row on the tape, the second group at the side of the first group but also longitudinal,

etc. Small connecting lines are utilized in the several figures to show the group podtions which are related to each other. In Fig. 11, the groups are arranged in threes wherein two transverse rows of a five unit code are utilized and the positions are triangular relative to each other. Fig. 12 illustrates a three unit code translated into a five unit code and in which the groups are transverse the five unit tape.

Referring now back to Figs. 6 and 7, these figures illustrate diagrammatically apparatus whereby the three unit code from Fig. 8 is superimposed on a five unit code in accordance with the tape shown in Fig. 10. The wiring of the polarized relays 28 relative to the distributors is in accordance with the pattern of Fig. 10, that is, the three unit distributor has its segments connected with the relay bank one below the other exactly as the code combination as shown in Fig. 10. In order to connect up the distributor relay bank shown in Fig. 6 to translate the arrangement shown in Fig. 11, it merely becomes necessary to wire the relay bank and the distributors in accordance with the pattern on the, tape illustrated in Fig. 11. plied both to the sending distributors and relay bank, and the receiving distributors and relay bank. The same observation applied to the pattern shown in Fig. 12 or as a matter of fact to any other pattern which may be chosen for superimposing one code system upon another.

Figs. 13, 14, 15, 16, and 17 relate to a different feature of the invention, namely, the relation of the light necessary to properly expose the sensitive film at the receiving station in order to give a proper gradation of tone from the original code signals. The speed of sensitiveness of a photographic film is in the order of a logarithmic curve. It follows, therefore, that to reproduce properly exposed unit areas in the copy so that these areas will correspond in tone to areas on the original, that the light falling on the film shall be in a logarithmic ratio. For example, choosing an arbitrary scale, the first tone is zero, being black no light passed to the film. The next has a light exposure value of one; the third, the light value should be two; the fourth, the light value should be four; the fifth, the light value required is eight; the sixth, the light value necessary is sixteen; the seventh, the light value should be thirty-two; and the eighth, the light value preferably is sixty-four. These light values of the exposure cause the film to be uniformly exposed in eight arithmetically graded shades or tones. This logarithmic ratio exposure may be brought about in various ways, one of which comprises the utilization of mirrors affecting light rays passing through a three unit tape as exposed through openings in the light tight box containing the film to be exposed. The paths of the light rays through the tape openings are restricted by suitable diaphragms so that the amount of light delivered to the film will be in accordance with the light values desired. It is to be understood that the light from the three openings in the tape shall be concentrated to illuminate a single unit area on the film in accordance with the sum of the light values passing through the said tape and diaphragm openmgs.

Referring to Fig. 13, it will be noted that each diaphragm opening is divided into four areas, certain of which represent light passing directly through the openings and others of which represent beams of light that are reflected to pass This pattern wiring, of course, ap

through other openings. It is to be understood that the tape acts as a. shutter, namely, no holes in the tape, no lightthrough the diaghragm openings; one hole in the tape, the correspond lng hole in the diaphragm is in use, etc. Referring now to the diaghragm illustrated in Fig. 14, the opening 88 passes one beam 89 directly through the opening to the film. The value of this beam in light intensity is one. It therefore follows ii. a single hole is punched in the tape in the position D at the left hand side, (Fig. 15) the light value passing the tape hole D and through the diaphragm opening 88 and striking the sensitive film will be of the order of one in the arbitrary scale. It the second or middle space on the tape corresponding to position H be punched, a light ray I0 passes through the opening and the value thereof is of the order two. If the two openings are punched in the tape corresponding to positions J and K,'then light my 69 goes directly through the opening 68, and light ray I0 goes directly through the opening I I, while light ray I2 originating through opening 88 strikes a reflector I4 and is reflected to reflector I5, then to reflector I8 and finally to reflector TI which directs this light ray I2 through the opening I I. It therefore will be seen that for this code combination, namely, J, K, the value of the light striking the film one plus one plus two totalling four. If the position 0 of the tape is punched, then a single light'ray 18 of the value eight passes through the opening I9. If the tape positions P and R are punched, then light ray B9 of a value of one passes directly to the film, light ray 18 of the value eight passes directly to the film and a light ray of the value seven originating through the opening 68 is reflected from a reflector 8| to the reflector I5, from there to reflector I5 and on to a reflector 82 which reflects this beam of the value seven through the opening 19. Therefore, for this combination, P and R, the total light value striking the film is sixteen made up of the beams 69, I8 and 80, having individual values 0t one plus eight plus seven. If the combination represented by the positions T and U in the tape is punched, then the value of the light striking the film is made up by the beam I0 passing directly through the opening II plus the beam 18 of the value eight passing directly through opening I9, and plus a beam 84 originating through the openings II striking reflector 85 is reflected to reflector I5, from there to reflector I8, from reflector 78 to reflector 82 and through the opening I9. The light value of this beam 84 is twentytwo so that for the combination T and U in the tape, the total light value striking the film is thirty-two made up of the beams I0, I8 and 84 having the light values of two, eight, and twentytwo. If the full code V, W, X, is punched in the tape, then the light striking the film comprises the beams 89, 70, l2, i8, 80, 84 and a ray 86 originating at the opening 88, striking the reflector I4 from there to reflector I5, to reflector Hi, to reflector 11, through opening II to reflector 85, back to reflector I5, back to reflector I6, and then to reflector 82 and through the opening I9. The value of this beam of light is twenty three. It therefore follows for the code V, W, X punched in the tape, the total light value reaching the film is sixty-four made up of beams 89, I0, I2, I8, 80, 84, and 88 having the values one plus two plus one plus twenty-two plug eight plus seven plus twenty-three. It is to be understood that the light ratios above specified relate to through three openings in the tape and be built up in such manner as to form a logarithmic scale of eight tone values considering zero as black.

The logarithmic scale from a three code tape may be approximated sumciently close to be satisfactory for practical purposes, by the use of a five code tape projecting through a suitable diaphragm. This is illustrated in Fig. 16 in which the three unit code has been translated into alogarithmic five unit tape. The diaphragm 8'! is provided with five graduated openings 88 to 92 respectively bearing the respective areas of one, two, four, twelve and fifteen. This diaphragm is adapted to control the light falling on the light sensitive film when a correction five unit tape 93 is fed over the diaphragm 81. The total amount of light falling on the light sensitive film will not be exactly in logarithmic ratio but the approximation is sufilciently close for practical purpose. This correction tape 93 may be made from the three unit code tape by the apparatus illustrated in Fig. 17. The three unit tape is read by a transmitter 83 to control selector magnets 94, 95 and 96. These magnets respectively operate notched control bars 91, 98 and 99 (well known in the art) The notches on these control bars are so arranged that when the notches are properly aligned, the drop levers I00 to I06 fall into the notches, however, the notches are so arranged that but one drop lever will drop at a time. When the control bars are in the position shown in Fig. 17, no drop lever can fall and, therefore, this position corresponds to black on the three unit code. It will be noted there are seven of the drop levers taking care of the seven tones other than black. These drop levers are adapted to control the selector magnets I 01 of a five unit punch in such manner as to produce the correction tape illustrated in Fig. 16, for example, when the drop lever I00 falls, the single selector magnet at the left is energized. When drop lever IOI falls, the second selector from the left is energized; when the drop lever I02 falls, the third selector is energized; when the drop lever I03 falls, the first, second and third magnets are energized; when the drop lever I04 falls, magnet 4 only is operated. When lever I05 operates, the first, second, third and fourth magnets are energized and when the drop lever I06 falls, all of the five magnets are energized. In connection with the disclosure of this Fig. 17 it is to be understood that operating devices, as is well known. in the art, are provided to operate the transmitter and to operate the punch and feed the tape.

Fig. 18 illustrates a transition from the three unit tape I I to the five unit correction tape 93, as performed by the device illustrated in Fig. 1'7.

While logarithmic ratios have been specified herein, it is to be understood that this same apparatus and methods may be used to produce other ratios which may be desirable, for example, in reproducing photographs by photo-engraving methods, certain tones are lost. In making a pic-- thesizing the picture on a diflerent arbitrary scale at the receiving station.

From the foregoing, it will also be observed that the present invention comprises superimposing one code used in analyzing a picture upon different code systems used for transmission wherein the two codes are diiierent and the present invention also contemplates the transition from an analyzing code to a logarithmic code adapted to, give correct photographic exposure. It is to be understood that a code signal may comprise one or more electrical impulses.

The present invention contemplates the superimposing of an analyzing code of narrow range upon a transmission code of wide range at the sending station, and synthesizing the wide range code into a narrow range code at the receiving station. This is exemplified by the fact that the basic code as illustrated (of three unit combinations) is a narrow range code, i. e., a code capable of only eight combinations while the transmission codes or the correction tape code is of much greater range including thirty-two and more combinations. The basic code will be referred to in the claims asa code of narrow range, while the transmission and correction codes will be referred to as wide range codes.

What I claim is:

1. The method of transmitting a picture which comprises scanning the picture to obtain signals as to light and shade in one code, and rearranging and transmitting the same said signals as a part of a different code.

2. The method of transmitting pictures comprising analyzing a picture into signals of a code having a narrow range, transmitting the signals on a wide range code and utilizing all the units of the wide range code during said transmission for shade elements.

3. The method of transmitting a picture comprising analyzing the picture into unit areas according to a light value code of less than ten combinations, superimposing the light value code upon a diiierent code having more than ten combinations and-filling each space of the difierent code by a portion of a signal from the light value code.

4. The method of transmitting pictures comprising analyzing the picture into unit areas according to a light value code, superimposing the light value code upon a different code whereby one signal of the light value code becomes a part of more than one signal of said different code.

5. The method oi transmitting a picture comprising analyzing the picture into unit areas valuated according to a light value code, superimposing said light value code upon a diiierent code of greater combinations and causing one signal of the light value code to cover a part of a plurality of signals of the said different code.

6. The method of transmitting pictures which comprises analyzing a picture into unit areas, making a record thereof according to a light value code of few units translating the record or the light value code into a transmission code of many units, and filling all of the code spaces of the transmission code with portions of signals from the light value code.

7. The method of transmitting pictures comprising punching a tone code tape in accordance with the tone values of unit areas of a picture, transposing the tone code tape into a transmission tape of a greater number of combinations than the possible combinations on the tone tape, causing a receiving instrument to reproduce a received tape comprising a replica of the transmission tape, transposing the received tape into a received tone code tape corresponding to the tone code tape at the sending station, and synthesizing a picture from the received tone code tape.

8. The method of transmitting pictures which comprises scanning a picture into unit areas and punching a three unit light code tape, transposing the signals from the three unit tape to a five unit tape and filling all of the code spaces on the five unit tape by portions of signals from the three unit tape, and utilizing the five unit tape for transmission purposes.

9. The method of transmitting pictures comprising the steps of scanning unit areas of the picture into eight light tone values, imposing a code for the eight light tone values upon a tape transmission system having a code combination in excess of eight and utilizing all of the signal spaces of said code transmission tape for shade elements.

10. The method of receiving a picture comprising receiving electrical impulses and making a code record of more than ten combinations, transposing said record and making a picture record in a code of less than ten possible combinations.

11. The method of receiving a transmitted picture comprising receiving the picture signals in a code of wide range, transposing the signals of the wide range code into a narrow range picture code, and synthesizing a picture from the signals in the narrow range code.

12. An apparatus for the transmission of pietures comprising means to scan a picture,-control means, a punch operated by said control means to punch a signal in a light code tape for the tone value of each unit area scanned, relaydistributor means controlled by the punched signals, a code transmission punch,-and mechanism controlled by the relay-distributor means for controlling said code transmission punch whereby the code in the light code tape is transposed into a transmitter tape of a different code.

13. An apparatus for the transmission of pictures comprising means to scan a picture, marginal relays controlled by said means, punch mechanism selectively controlled by said marginal relays to punch records of code signals in a tape to record the tone value of each unit area scanned, a distributor having commutators equalling in number the units of the code punched in said tape, a bank of polarized relays having the energizing coils thereof connected with segments of said commutators, a second distributor having a second group of commutators equalling in number the units of a different code system, the contacts of said relays being connected with the segments of the second mentioned commutators, said second mentioned commutators operating to produce code signals from the first mentioned distributor in the form of the code determined by the second mentioned distributor.

14. An apparatus for the transmission or reception of pictures comprising a distributor having commutators equalling in number the units of a code system, a bank of relays having the energizing coils thereof connected with segments of said commutators, a second distributor having a second group of commutators equalling in number the units of a difi'erent code system, the contacts of said relays being connected with the segments of the second mentioned commutators, said second mentioned commutators operating to produce code signals from the first mentioned distributor in the form of the code determined by the second mentioned distributor.

15. In an apparatus for transmitting pictures, means to scan the picture into unit areas and analyze the light value thereof into a light value code, and devices for transposing the light value code signals into transmission code signals or a different code system.

16. An apparatus .i'or picture transmission comprising means to analyze the picture into unit areas according to a light value code of less than ten combinations, and devices for translating the light value code signals into a different code of more than ten combinations.

and filling each space of the different code with a portion of a signal from the light value code.

17. An apparatus for transmitting pictures comprising means to scan the picture into unit areas, and to produce electrical currents dependent upon the light values of said areas, said electrical currents being produced according to a predetermined combination of eight light tone values, and devices whereby said electric currents control means to establish a second group of electric currents operative in accordance with a second code combination in excess of eight and utilizing all of the signal spaces in said second code combination for picture tone elements.

18. An apparatus for transmitting pictures comprising means to scan a picture into unit areas of eight light values, punch mechanism to record a three unit code signal in a tape for each or said eight light values, means controlled by said three unit tape to produce a five unit transmission tape carrying the said light value code signals and utilizing all of the signal spaces of the said five unit code tape during transmission.

19. In a device for transmitting pictures, the combination of means to produce a three unit code tape capable of registering eight light tone values from black to white, and translating means to translate said three unit tape into a five unit tape carrying the same code signals as those on the three unit tape and utilizing all of the code spaces on said five unit tape.

20. In a picture transmitting system, means to scan a picture and record three unit code signals transversely of a three unit code tape and devices to record the three unit code signals longitudinally in transverse rows on a tape of a transmission system having more than three units as a code system.

21. In a device of the class described, means to scan a picture on one code system, and devices to transpose and transmit the scanned code signals on another code system.

22. In a picture transmission system, means to record tone values of picture areas in code signals progressively punched along a tape, means to read said code signals transversely of said tape in groups equalling in code signal units the number of units in a transmission code, and means to record progressively along a transmission tapein said transmission code the said transverse readings of said code signals.

23. The method of producing a photographic replica of an original picture comprising scanning the original into unit ar'eas, recording tone values or said unit areas in a narrow range code and according to an arithmetical scale between the limits of black and white, controlling beams of light greater in number than the number of the units in the narrow range code and capable of being combined to form a logarithmic light scale, and exposing a sensitive film to the said beams, whereby said sensitive film is exposed to produce equally graduated tones between predetermined limits of black and white.

24. The method of producing a photographic replica of an original picture comprising scanning the original into unit areas, recording tone values of said unit areas in a narrow range code and according to a non-photographic scale between the limits of black and white, controlling beams of light greater in number than the number of units in the narrow range code and capabis of being combined to form a photographic scale whereby a sensitive film is exposed to produce equally graduated tones between predetermined limits of black and white.

25. The method of reproducing pictures comprising scanning the original picture into predetermined light tone intervals of an arbitrary scale, producing a record comprising a narrow range code with sufiicient combinations to cover said arbitrary scale, controlling a plurality of beams of light greater in number than the units code on said received tape, and devices operated.

by said means to synthesize a picture from the picture code signals.

27. In a picture transmission system, a light sensitive device, means to scan a picture whereby said light sensitive device varies an electrical current in accordance with the tone variations of small areas of said picture, means under control of said current to register at predetermined intervals code combinations corresponding to the variations of said current, transmission devices operating under a different basic code combination and under control 01' said means to produce transmitted signals, means to receive the transmitted signals, devices to transpose the received signals into picture signals in a code combination corresponding to the code combination on which the picture was scanned, and devices to synthesize a picture from the said picture signals.

28. In a picture transmission system, means to equalling in number the units of the picture analyzing code, a bank of polarized relays with each operating magnet of said relays connected to a commutator segment'of said distributor, a second distributor having commutators equalling in number the units of a transmission code, the segments of the commutators oi the second distributor being connected with the contacts of said polarized relays, the said second distributor being connected with punch magnets to punch a transmission tape.

30. In a picture transmission system, a light sensitive device, means to scan a picture whereby said light sensitive device varies an electrical current in accordance with tone variations or small areas of said picture, means under control of said variable current to produce tone code combinations in accordance with the variations of said current, transmission devices operating under a diiIerent basic code combination to transmit the tone code combinations determined by said variable current, means to receive the transmitted signals, devices to transpose the received signals into picture signals, and mears to synthesize a picturefrom said picture signals,

31. In a picture transmission art, the method of tape shortening comprising scanning an original into a series of picture tone code signals on a code of narrow range, transposing the narrow range code signals onto a code of wide range whereby the picture tone code signals are condensed into a shorter linear series of signals.

32. In the picture transmission art, the combination of means for scanning a picture and producing an electrical current which varies in accordance with the tone shades of small areas of the picture, recording means to make a record tape, means to operate said recording means at predetermined intervals to record on said tape the variations of said current, the record of said variations being recorded in a predetermined code, said code having less elements than the number of distinctive variations of said current, and means under control of said record tape to make a transmission tape having different code elements from the record tape and in which transmission tape each record in the record tape is represented.

33. An apparatus for the transmission of pietures, means to scan a picture and produce an electrical current which varies in accordance with the light and shade of each small area of said picture, means to register a picture tone code signal for each said small area of the picture, and means controlled by said registered tone signals to produce a transmission signal for each of said registered tone signals and with said transmission signals arranged in a different code from the code in which said picture tone signals were registered.

34. An apparatus for the transmission or pictures, means to scan a picture and produce an electrical current which varies in accordance with the light and shade of each small area of said picture, means to register a picture tone code signal for each said small area of the picture, and means controlled by said registered tone signals to produce transmission signals, each of which comprises portions of at least two tone code signals.

35. The method of reproducing a picture from an original comprising scanning the original into unit areas, and recording the light tone value of each unit area in a code, said cole having less elements than the distinctive light tone values which may be recorded therein, utilizing said record to control a greater number of light beams than there are elements in said code, combining said beams 01 light, and synthesizing a picture therefrom.

36. In a picture synthesizing apparatus, a tape provided with a plurality of openings therein comprising records of picture tone signals, means to direct beams of light through the openings in said tape, and means to pass a single beam of light through a plurality of openings in said tape.

3'7. The method of receiving a transmitted picture comprising receiving the transmitted signals in a code of wide range wherein each of said signals comprises a portion oi a plurality of picture signals of a narrow range code, representing light values of unit areas of a picture, transposing the transmitted signals 01 the wide range code into individual picture signals in a narrow range picture code, and synthesizing a picture from the picture signals in said narrow range code.

38. The method of reproducing a picture from an original comprising scanning the original into unit areas, translating the light tone values of said unit areas into a code of electrical signals, each of said code signals having less elements than the distinctive light tone values which may be transmitted by the said code signals, utilizing the said code signals to control a greater number of light beams than there are elements in said code signals, combining said beams of light, and synthesizing a picture therefrom.

39. In a picture receiving apparatus, means to receive picture tone signals, a source of light, a plurality of apertures to produce beams of light from said source of light, and means under control of said tone signals to reflect certain of said beams of light to repass the same through said apertures whereby a larger number of beams of light are caused to pass through said apertures than there are numbers of apertures.

MAYNARD D. MCFARLANE. 

